Wideband code division multiple access (Wideband Code Division Multiple Access; abbreviated as WCDMA hereinafter) as a widely used 3G technology in the world at present provides voice and data services for a user. Multiple input multiple output (Multiple Input Multiple Output; abbreviated as MIMO hereinafter) technology can provide higher data throughput by using multiple paths without occupying extra radio frequencies. Therefore, the application of the MIMO technology in a WCDMA system can improve the system capacity. High speed downlink packet access (High Speed Downlink Packet Access; abbreviated as HSDPA hereinafter) is a critical technology for improving data throughput introduced in release R5 of WCDMA standard, and in WCDMA standard, a closed-loop transmit mechanism of a double-transmit antennas array (Double-Transmit Antennas Array; abbreviated as D-TxAA hereinafter) and a closed-loop transmit diversity mode of a single-transmit antenna array (TxAA) are used to implement MIMO. In the downlink link of the WCDMA system, signals of a user are affected by interference including inter-cell interference and intra-cell interference, so interference elimination needs to be considered in demodulation.
In the prior art, a minimum mean squared error (Minimum Mean Squared Error; abbreviated as MMSE hereinafter) equalizer is generally used to eliminate the interference, that is, a transmitted signal on one of two transmit antennas is modeled as interference, and the interference of the transmit antennas is eliminated by an equalizer.
In the implementation of the present invention, the inventor finds that the prior art has the following problems. The MMSE equalizer in the prior art does not consider correlation between transmitted signals on two transmit antennas, causing undesirable equalization effect and low performance of a receiver.